1. Field of the Invention
The present invention generally relates to a method and a device for automatic color correction and, more particularly, to a method and a device for automatic color correction by using an operation window and a target window.
2. Description of the Prior Art
With the arrival of the digital era, digital information products are replacing analog products. One example is that the digital TV gradually replaces the traditional analog TV. Meanwhile, the video information is recorded and distributed by digital media instead of traditional tapes. Consequently, the quality of digital images has become a major issue in the industry.
The digital image is recorded in pixels. The colors of each pixel associated with its brightness and chromaticity, are seen as various combinations of the so-called primary colors, red (R), green (G), and blue (B). Moreover, the quality of digital images primarily depends on the brightness, contrast, and chromaticity of the whole picture.
As for digital image processing, the prior art converts RGB signals into luminance (Y) and chroma (U and V) signals, and then adjusts these signals to increase the brightness, contrast, and chromaticity of digital images.
Taking correction of chroma signals for example; a conventional method for adjusting chroma signals lies in the automatic correction of chroma signals in a region where its chroma is insufficient in the image picture. Besides, the chroma values are adjusted to converge at the center of the region automatically so as to present the picture more vividly and display required color tones.
In the prior art method, although the chroma signals in a region where its chroma are insufficient can be automatically adjusted to converge at the center of the region, this simple approach leads to other problems in that the adjusted picture tends to monochrome and causes disharmony in the chroma between adjacent regions.
Therefore, there is need in providing a method and a device for automatic color correction such that the chrominance of the video can be adjusted automatically, and the adjusted image frame looks continuous and harmonious in chroma between adjacent regions.